Wyniki wyszukiwania - BazTech

1

Static and dynamic test analysis of a 12-years old 14 000-ton cable-stayed bridge used swivel construction technology

Liu Meng, Sun Quansheng, Yu Haitao, Yang Jianxi, Zhang Tongzhou

Archives of Civil Engineering

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2021

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Vol. 67, nr 4

369--381

EN

In order to study the change in performance of the Suifenhe cable-stayed bridge in China over 12 years, cable force, elevation, static and dynamic load tests were conducted in 2006 and 2018, respectively. In this paper, theoretical data, obtained through finite element model analysis, were compared with the measured load test data for changes in static and dynamic performances. A comparison between 2006 and 2018 shows that additional dead load deflection exists in the main span after 12 years of operation. And that the cable force due to dead load of the full-scale cable-stayed bridge decreases and redistributes, which have adverse effects on the safety of bridge structure after long-term operations. Therefore, on-site inspection, static and dynamic load tests are recommended for cable-stayed bridges over 10-years old to test their static and dynamic performance. Moreover, cable force adjustments are to be conducted whenever necessary for the cable-stayed bridge used swivel construction.

2

Measurements of rope elongation or deflection in impact destructive testing

Szade A., Szot M., Ramowski A.

Journal of Sustainable Mining

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2015

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Vol. 14, iss. 4

211--218

EN

The computation of energy dissipation in mechanical protective systems and the corresponding determination of their safe use in mine shafts, requires a precise description of their bending and elongation, for instance, in conditions of dynamic, transverse loading induced by the falling of mass. The task aimed to apply a fast parallactic rangefinder and then to mount it on a test stand, which is an original development of the Central Mining Institute's Laboratory of Rope Testing in Katowice. In the solution presented in this paper, the measuring method and equipment in which the parallactic laser rangefinder, provided with a fast converter and recording system, ensures non-contact measurement of elongation, deflection or deformation of the sample (construction) during impact loading. The structure of the unit, and metrological parameters are also presented. Additionally, the method of calibration and examples of the application in the impact tests of steel wire ropes are presented. The measurement data obtained will provide a basis for analysis, the prediction of the energy of events and for applying the necessary means to maintain explosion-proofness in the case of destructive damage to mechanical elements in the mine atmosphere. What makes these measurements novel is the application of a fast and accurate laser rangefinder to the non-contact measurement of crucial impact parameters of dynamic events that result in the destruction of the sample. In addition, the method introduces a laser scanning vibrometer with the aim of evaluating the parameters of the samples before and after destruction.

3

Ocena zużycia korozyjnego lin stalowych metodą magnetyczną

Tytko A.

Przegląd Górniczy

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1999

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T. 55, nr 2

31-34

PL

Zużycie lin stalowych na skutek korozji powoduje powstawanie różnych produktów ubocznych na skutek utleniania się materiału drutów. Niektóre z tych produktów, zalegające na powierzchni i wewnątrz liny, mają właściwości magnetyczne, podobnie jak druty liny stalowej. Takie produkty korozji znajdujące się w linie mają wpływ na wyniki badań magnetycznych, gdy używana jest aparatura wykorzystująca hallotronowe czujniki pomiarowe, co może prowadzić do przecenienia wytrzymałości liny. Badania mające na celu określenie takiego wpływu były wykonywane w Kanadzie i Australii. W artykule autor przedstawia niektóre wyniki badań wpływu produktów korozji na odczyty sygnału czujnika hallotronowego, wykonane polskim defektografem MD 120. W artykule przedstawiono także sposób kalibracji statycznej i dynamicznej czujników hallotronowych za pomocą prętów stalowych i drutów linowych.

EN

Corrosive wear of wire ropes causes formation of various by-products because of wires material oxidation. Some of those products deposites on the surface and inside the rope have magnetic properties similarly as the wires of the wire rope. Such corrosion products being in the rope have an influence on the results of the magnetic tests when an apparatus based on Hall-effect sensors is used, what may bring to overestimate of the rope strength. Tests aimed to determine such influence have been performed in Canada and Autralia. The authors presents some results of the teste of influence of corrosion products on the Hall-effect sensor signal reading made by means of the Polish defectograph MD 120. the procedure of ststic and dynamic calibration of the Hall-effect sensors by means of steel rods and rope wires is also presented.